Automatic control systems are widely used in construction machines. The use of automatic control systems in construction machines improves the accuracy of work performed using construction machines, cuts fuel and construction material consumption, brings down skill requirements for operating construction machines, and reduces fatigue of construction machine operators. For example, automatic control systems are used to control grader and bulldozer blades, asphalt and concrete pavers, and excavator buckets. Such automatic control systems are typically used to hold the operative organ of the machine at a desired height to track a design project. To estimate the current height of the operative organ, different sensors are employed, such as Global Navigation Satellite System (GNSS) sensors, laser sensors, ultrasonic sensors, etc. The drawbacks of such sensors include infrequent update rate, delay in response time, and poor short-term stability. To solve these issues, the sensors are often integrated with inertial sensors, such as angular rate sensors (gyroscopes) and/or accelerometers, installed on the machine.
Unfortunately, construction machines are subject of shock and vibration impacts with high level amplitudes that are caused by the working movements of the construction machines, and such impacts negatively affect the inertial sensors. This problem is particularly prevalent for bulldozers and excavators. The impacts are often caused by stones either hitting a blade or bucket or falling into a vehicle's base mounting (for example, between a track and rollers). Similar impacts can also be caused by a hydraulic rod, if there is an air gap at the pivot point to the blade. Rollers themselves moving on tracks (especially at the point of track shoes connection) also create vibration impact. The influence of such impacts, especially in the 1 kHz or higher frequency range, negatively affects the proof mass stability, which is a measuring element of inertial sensors of micromechanical types (e.g., MEMS—micro electro mechanical system). This is the micromechanical sensor (MEMS sensor) that is the most widely utilized due to its high accuracy, reliability, compactness, and low cost.
Shock and vibration impacts on the construction machine can result in errors in a sensor's output signal. Fortunately, sensors have a selectivity to impact frequencies. There are frequencies to which the proof mass is sensitive and frequencies to which the proof mass is insensitive. Both accelerometers and gyroscopes are built on the basis of a mechanical oscillating/vibrational circuit with some internal frequencies. If in the spectrum, there are harmonics equal to the resonance frequency, an error is generated. It is desirable that such frequencies need to be mechanically filtered. Accordingly, a shock absorption system that prevents impacts of such frequencies from being transferred to the sensor is desirable.